vbscript Visual Basic 2013 Mysql数据库连接

Posted 2021-05-22

Private Sub buttonRegister_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonRegister.Click

        'Does user already exists
        Dim bUserExists As Boolean = _Users.UserExists(New UserID(textBoxUserName.Text))

        ' first make sure the user is created if new user
        If _ActiveUser Is Nothing Or Not bUserExists Then
            ' initialize with supplied user name
            _ActiveUser = New User(textBoxUserName.Text)
        Else
            ' update active user if not as originally selected
            If bUserExists And Not listBoxUsers.SelectedItem.ToString() = textBoxUserName.Text Then
                _ActiveUser = _Users(New UserID(textBoxUserName.Text))
            End If
        End If

        ' and check if the template already exists for the assigned finger
        If _ActiveUser.TemplateExists(_AssignedFinger) Then
            ' show message indicating template already exists for selected finger
            Dim diagResult As DialogResult = MessageBox.Show(Me, [String].Format("Oops!" + ControlChars.Cr + ControlChars.Lf + "{0} has a template enrolled to his/her {1} finger." + ControlChars.Cr + ControlChars.Lf + ControlChars.Cr + ControlChars.Lf + "Shall the old template be discarded?", _ActiveUser.ID.ToString(), _Fingers(_AssignedFinger)), "Template already assigned!", MessageBoxButtons.YesNo, MessageBoxIcon.Error)

            ' if user selected not to overwrite, then abort
            If diagResult = Windows.Forms.DialogResult.No Then
                Return
            End If
        End If

        Try
            ' attempt to read the template
            Dim templateOpened As New DPFP.Template(File.OpenRead(textBoxTemplateFilename.Text))

            ' run a template duplicate check
            IdentifyTemplate(templateOpened)

            ' remove the old template if exists
            If _ActiveUser.TemplateExists(_AssignedFinger) Then
                ' removed from assigned finger
                _ActiveUser.RemoveTemplate(_AssignedFinger)
            End If

            ' and assign it to the user as specified
            _ActiveUser.AddTemplate(templateOpened, _AssignedFinger)

            ' update collection
            If Not _Users.UserExists(_ActiveUser.ID) Then
                ' update list box
                listBoxUsers.Items.Add(_ActiveUser.ID.ToString())

                ' add user it to the user collection
                _Users.AddUser(_ActiveUser)
            End If

            ' success
            UpdateEventLog([String].Format("{0}: Template successfully assigned to {1} finger.", _ActiveUser.ID.ToString(), _AssignedFinger.ToString()))

            ' turn off groupbox
            groupAddTemplate.Visible = False

            listBoxUsers.SelectedItem = _ActiveUser.ID.ToString()

            ' sync gui
            _syncUI()

            ' view user
            _syncViewUser()

        Catch Err As DPFP.Error.SDKException
            ' log message
            UpdateEventLog(Err.ToString())
            System.Diagnostics.Trace.WriteLine(Err.ToString())
        Catch Err As System.IO.FileNotFoundException
            ' log message
            UpdateEventLog("Template file not found or is inaccessible.")
            System.Diagnostics.Trace.WriteLine(Err.ToString())
        Catch Err As Exception
            ' log message
            UpdateEventLog(Err.ToString())
            System.Diagnostics.Trace.WriteLine(Err.ToString())
        End Try

        Using conn As New MySqlConnection("Server = localhost; Username= root; Password =; Database = vb")
            Using cmd
                With cmd
                    MsgBox("Connection Established")
                    .Connection = conn
                    .Parameters.Clear()
                    'Create Insert Query
                    .CommandText = "INSERT INTO employees(UserID, Name, Finger) VALUES (@iID, @iName, @iFinger)"
                    .Parameters.Add(New MySqlParameter("@iID", ID.Text))
                    .Parameters.Add(New MySqlParameter("@iName", textBoxUserName.Text))
                    .Parameters.Add(New MySqlParameter("@iFinger", comboBoxAssignedFinger.Text))


                End With
                Try
                    'Open Connection and Execute Query
                    conn.Open()
                    cmd.ExecuteNonQuery()
                Catch ex As MySqlException
                    MsgBox(ex.Message.ToString())
                End Try
            End Using
        End Using

Imports MySql.Data.MySqlClient
Public Class Form1
    Public dbconn As New MySqlConnection
    Public sql As String
    Public dbcomm As MySqlCommand
    Public dbread As MySqlDataReader

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        dbconn = New MySqlConnection("Data Source=localhost;userid=root;database=vb;")
        Try
            dbconn.Open()
        Catch ex As Exception
            MsgBox("Error in connection, please check Database and connection server.")
        End Try

    End Sub

    Private Sub btn_save_Click(sender As Object, e As EventArgs) Handles btn_save.Click
        sql = "INSERT INTO users(username) VALUES('" & text_user_name.Text & "')"
        Try
            dbcomm = New MySqlCommand(sql, dbconn)
            dbread = dbcomm.ExecuteReader()
            dbread.Close()
        Catch ex As Exception
            MsgBox("Error in saving to Database. Error is :" & ex.Message)
            dbread.Close()
            Exit Sub
        End Try
        MsgBox("The User Name was saved.")
        text_user_name.Text = ""
    End Sub

    Private Sub btn_get_Click(sender As Object, e As EventArgs) Handles btn_get.Click
        list_users.Items.Clear()
        sql = "SELECT * FROM users"
        Try
            dbcomm = New MySqlCommand(sql, dbconn)
            dbread = dbcomm.ExecuteReader()

            While dbread.Read
                list_users.Items.Add(dbread("username"))
            End While

            dbread.Close()
        Catch ex As Exception
            MsgBox("Error in collecting data from Database. Error is :" & ex.Message)
            dbread.Close()
            Exit Sub
        End Try
    End Sub
End Class